Anti-friction bearings may serve to decrease friction between, for example, a stator and a rotor. For instance, such bearings may allow relative rotation between a housing and a spindle extending through the housing. The housing may comprise, for example, a hub. The spindle may comprise a shaft, axle, or the like. The bearings may comprise roller bearings, for example, tapered roller bearings. In one example, the tapered roller bearings may be employed in wheel hub and axle assemblies. In another example, the tapered roller bearings may be employed in devices such as motors, pumps, or speed reducers.
A typical tapered roller bearing may include a cone having an inner race for mounting on a spindle, a cup having an outer race for mounting in a housing, and a plurality of roller elements within a roller cage positioned between the inner and outer races. Commonly, a pair of such tapered roller bearings may be mounted on a spindle for rotation relative to or within a housing. Cooperating bearings, such as a pair of tapered roller bearings, may be included in a bearing assembly, for instance, of a motor, pump, speed reducer, or transmission assembly. In one example of "direct mounting" of the tapered roller bearings, the cups may be located in the bearing assembly axially outward relative to the cones. With exemplary "indirect mounting" of the tapered roller bearings, the cups may be located in the bearing assembly axially inward relative to the cones, as will be understood by those skilled in the art.
In order to properly secure bearings for operation, it is usually necessary to retain the bearings tightly under a predetermined axial tolerance or load on the spindle, for example, so that the bearings can maintain a proper running clearance of the roller elements under the influence of the combined axial and radial forces which the bearings are designed to support. Manufacturers of such assemblies often carefully measure the space between the bearing inner races, and provide a spacer of precisely the correct dimension and load requirements to fit therebetween. The spacer is typically made of ground steel tubing to a length tolerance of plus or minus one half of one thousandths of an inch. If the bearings are not maintained at a proper tolerance and/or load the bearings may not roll properly or may prematurely wear, particularly if the bearings are maintained at too high of a load, or may, if maintained under too low of a load, have excessive play causing failure of the bearings.
An exemplary configuration for an adjustable spacer is disclosed in U.S. Pat. No. 5,549,397 to John E. Rode (entitled "Adapter Sleeve and an Adjustable Spacer with Radial Extension Useable Thereon," issued Aug. 27, 1996, and assigned to Temper Corporation), which is hereby incorporated herein by reference in its entirety. In one embodiment, such an adjustable spacer may be of a type shaped as a ring for mounting between a pair of tapered bearings mounted on an axle or spindle to allow a load to be axially placed on the bearings. The adjustable spacer may include an extension located at a radius from an imaginary axis of the spacer, a contact means oriented radially outward from the extension, and a compressible area located between the contact means and the extension wherein the compressible area deforms when a predetermined load is applied to the ring in the axial direction. The adjustable spacer may be configured to be used with an adapter sleeve for use on axles or spindles of multiple radii.
In a further example, a deformable portion of such an adjustable spacer may be formed so that the spacer can be compressed axially and react with a generally constant force as described in U.S. Pat. No. 4,067,585 to John E. Rode (entitled "Deformable Metallic Element," issued Jan. 10, 1978, and assigned to Temper Corporation), which is hereby incorporated herein by reference in its entirety.
In addition, an illustrative configuration for a bearing assembly adjustment gaging system is disclosed in the above-incorporated Application Ser. No. 09/130,166. In one example, such an adjustment system may include a first gage part adjustably engaged (e.g., mated and/or threaded) with a second gage part. The gage parts may be employed in a (e.g., pressing) process of direct installation of bearings such as tapered roller bearings on a final assembly spindle as in a motor, pump and/or speed reducer shaft. Also, one or more of the gage parts may be employed in providing adjustments (e.g., a preload and/or an endplay setting) for an adjustable spacer during the same process of direct installation of the bearings. The gage parts may have various interfaces with the bearings, retainers, and/or housing portions, rotationally supported with respect to the spindle with the bearings. Further, the gage parts may serve to protect the bearings from paths of compression employed in the adjustments.
One technique for accomplishing such adjustment to the spacer by crushing the bearings together, sometimes using the gage parts, employs a mechanical press. The bearing assembly can usually be deemed to be correctly adjusted when a relatively light rolling drag force is detected to be present in the bearings, at which point it is typically important to stop further compression of the spacer before a relatively heavier rolling drag occurs.
For instance, the mechanical press may utilize a screw which is slowly driven to bring the plates or platens together under operator control. Such screw driven presses are usually larger and much more expensive than a hydraulic press of comparable capacity. However, a hydraulic press commonly has less accuracy and consistency of bearing adjustment than the screw driven press.
Thus, a need exists for improving ease, accuracy, performance, repeatability and/or control of adjustment to an adjustable spacer of a bearing assembly. A need also exists for decreasing the degree of operator judgment and/or skill required (e.g., by introducing automation and/or indicators, such as for mass production situations and/or arrangements) to properly adjust the spacer. An additional need exists for decreasing dimensional measurements required to properly prepare a bearing assembly and/or a spacer thereof. Another need exists for the adjustable spacer to allow a desired adjustment to be provided for the bearing assembly.